Knee-joint mechanism for artificial limbs



J. F. ROWLEY.

KNEE JOINT MECHANISM FOR ARTIFICIAL LIMBS. APPLICATION FILED APR. 19, 1920. 1,385,953.

Patented July 26, 1921.

, tfmasjifjfazaZgf UNITED STATES PATENT OFFICE.

JAMES F. ROWLEY, OF CHICAGO, ILLINOIS.

KNEE-JOINT MECHANIQM FOR ARTIFICIAL LIMBS.

Application filed April 19, 1920. Serial No. 374,948.

To all whom it may concern:

Be it known that I, JAMES F. Rownur, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Knee-Joint Mechanism for Artificial Limbs, of which the following is a specification.

The main objects of this invention are to provide an improved form of knee-joint actuating mechanism for artificial limbs of the general, character shown in my Patent No. 1,258,710; to provide improved means of the character stated, adapted fora wider angular range of positive operation at the will of the wearer; to provide an improved form of joint actuating lever and cord bearing therefor; to provide a slip bearing adapted to serve the purpose of a pulley but of larger radius; to provide such a bearing on one of the arms of said lever adaptedto increase the effective length of the cord arm of the lever as the joint is flexed; to provide an improved form of cord guide and a better arrangement of the actuating cord relative to the hinge pivot and lover; and to provide cord actuated means of the character described adapted to effect quiet and reliable operation and to avoid looseness of the parts. a r

An illustrative embodiment of this invention is shown in the accompanying drawings, in which- I Figure 1 is a longitudinal section through the limb from front to back on the line 11 of Fig. 2. 1

Fig. 2 is a cross-section of they limb as a whole just above the joint, at the line 22 on Fig. 1.

Fig. 3 is a fragmentary sectional enlargement showing the hinge joint lever'and adjacent parts, as viewed on the line 3-3 of Fig. 2.

Fig. & is similar to knee flexed.

In the construction shown in the drawings the artificial leg 1 is provided with a kneejoint 2. connecting the upper and lower leg members 8 and 4 which are of hollow construction. The upper member 3 is closed at its lower endand extends somewhat into the open upper end of the lower member. Said joint is hinge-like and includes a pivot bolt 5 secured at its ends in the duly apertured overlapping parts of said leg members.

Fig. 1, but with the The said lower part or shin member 4 is provided with a lever arm 6, mechanically unitary and rigid therewith, for actuation of the joint by means of the usual Suspender means as will be understood, though only the lower loops 7 of the Suspender device are shown.

Said arm 6 is secured to the shin member 4- in the following manner. The inner end of arm 6 is rigidly secured to the middle of the hollow pivot 5 as at 8, and the latter is rigidly secured at its end to the upwardly projecting ears or lugs 9 which are substantially integral with the walls of shin member 4. Moreover the other arm 10 of said lever has its remote lower end fixed to said member 4:, as at 11. Hence the shin member 4 as a whole is substantially the long arm of a lever the position of which relative to the thigh member 3 is controlled by the short arm 6 andv suspender l. The thigh member 3 is provided with a vertical slot 12 on its rear side to accommodate the lever arm 10 as the limb is flexed. Movement in straightening the limb is arrested by the arm or check 10 contacting with the lower end of slot 12 as at 13. The reverse movement is arrested by the edge 14 of part 4 contacting with part 3st the point 15.

The arm 6 is forwardly disposed andis about perpendicular to the main axis of the shin member, so as to straighten the leg when an upward pull is applied to the tip of said lever which is provided with a new and special form of cord bearing means to be described.

The said short arm is provided with a pair of arcuate cord bearings 16 disposed one on each side in vertical planes said bearings be ing of oblong tubular shape and curved somewhat, as will bemore fully described. Said bearings are secured pivotally to said arm 6 intermediately of their ends, and relatively near their forward ends the rearward ends being disposed to bear upward against said pivot 5 when swung to the limit of their movement in one direction;

More in detail the end of the lever is pro.- vided with a transverse pivot pin 17 and said bearings are secured to the outer ends thereof, the ends of the pivot being sweated to said bearings. In order to insure quiet operation and permanent lubrication of the pivot forsaid bearings,the outer end of said arm 6 is provided with a circular perforaof this invention tion 18 to receive said pin and a slot 19 is provided in the end of said arm extending inward to said perforation. The pivot is embraced by a roll of leather'or the like 20, adapted to retain lubricating oil. The edges 21 of said roll are disposedoutwardlyin said slot. The leather serves as a lock to hold the pin 17 in place. When the leather is re moved the pin 17 may be slipped out sidewisethrough said slot 19. This provides a loose, but quiet operating bearing for the Suspender. The tips 16' and '16 of said bearings 16 on their inner sides are extended slightlyiand are curved inward or rounded somewhat, so as to avoid any sharp edges.

The cords 7 coacting with said bearings extend through the tubular openings thereof and around the lower side of the main pivot.

Backward j and forward movement at the hips causes the cords 7 to merely slide through the bearings 16. When the knee is flexed as in Fig. Atthe whole force of the cord pull is applied directly tolever 6, but as the'members 3 and 4 swing more nearly into alinement the rearward part ofthe cord swings forward and upward against the hinge bolt 5, and from then on the force is applied partly-to said bolt and the direction of the net effective pull onlever 6 is diagonally upward and rearward. Referring again to Fig. l -it will be'noted that when the joint is flexed the effective length of lever 6 is increasedby reason of members 16, whereby the straightening force may be applied more efliciently and a less degree of tension is required on said cords.

The arcuate guide bearing 16 though occupying much less space than a pulley of similar radius and curvature ofiers all the advantages'ofsuch a pulley and the further advantage of light construction and positive direct guidance of the cord; It has been found that small pulleys are very destructive to the suspenders owing to the resultant sharp?- working bends, but this is; mainly overcome by the wide-loop turnsresulting with my-improved bearings 16. 1

Although but one specific embodiment of this invention is herein shown and described, it isto beunderstood that numerous details of the construction shown may be altered or omitted without departing fromthe spirit as defined by the following claims. r I claim:

1. An artificial leg comprising a thigh member and a shin memberconnected by means of a hinge joint, said" shin member having a cord bearing at its upper end in front of the hingeaxis,and a Suspender loop disposed downwardly in said thigh member and extending around the lower side of the hinge "pivot and said cord-bearing.

2. Inan artificial leg, aknee-joint includ ing apivot for the thigh and shin members,

a lever virtually fulcrumed on said pivot and havingone arm secured to one of said members, said lever having another arm on the free end of which is pivoted an arcuate end of 'which'is pivoted an arcuate tubular cord-bearing disposed in a plane perpendicular to and with itsconcave side disposed toward said pivot, one end of saidbearing projecting sufliciently to bear against said pivot for limiting its movement 4. In an artificial limb, a joint including a lever provided with a pair of cord-bearings at its outer end, said lever having a transverse perforation with a pivot therein, whereon said bearings are mounted and said lever having a slot disposed lengthwise of the pivot perforation and a leather bushing surrounding said pivot with itsedges disposed in said slot. 7

5. An artificial leg having a knee-joint including a hinge pivot, a lever fulcrumed thereon, one arm of said lever being secured to the shin member and the other arm being disposed forwardly at an angle with the main axis of said shin member and a tubular cord guideway-of arcuate shape pivoted to the free end of said other arm, one end of said guideway normally being disposed downwardly and rearwardly from its pivot and its relatively shorter opposite end being disposed forwardly and upwardly.

6. An artificial leg having a knee-joint including a hinge pivot, a lever fulcrumed thereon, one arm of said lever being secured to the shin member and the other arm being disposed forwardly at an angle with the main axis of said shin member and a tubular guideway of arcuate shape disposed in a vertical plane and pivoted medially of its-length somewhat nearer its forward end and its opposite end being disposed to contact-against the lower side of the hinge pivot whereby the movement of said guideway in one direction is limited, in combination with a cord loop extending downward in the thigh member through said guideway and around the lower side of the hinge pivot. 7. An artificial leg having aknee joint including a hinge pivot, a lever fulcrumed thereon, one arm of said lever being secured to the shin member and the other arm being disposed forwardly at an angle with the main axis of said shin'member, and a cord guideway of tubular character and arcuate shape pivoted to the free end of said arm.

8. In an artificial leg, a knee-joint connecting the thigh and shin members said shin member having an arcuate tubular cord bearing disposed in front of and in a'plane perpendicular to the joint axis.

9. In an artificial knee-joint, a lever rigid With the shin member and provided With a pair of arcuate tubular cord bearings at its outer end, said lever having a transverse perforation with a pivot therein, Whereon said bcarin 's are mounted.

10. in artificial leg including thigh and shin members hinged together at the knee, said shin member having an eccentrieally pivoted arcuate cord-bearing in its upper front part said bearing being disposed in a plane perpendicular to the knee hinge axis With its convex side facing downwardly and a suspender cord loop extending downwardly from the thigh member and around said cord-bearing.

11. An artificial limb joint, comprising a hinge pivot, a lever virtually ifulcrumedthereon having one arm secured to one of the limb members and another arm disposed transversely of the main axis of said memher, and an actuating cord loop disposed lengthwise of the other limb member and extending around said pivot and slidably attached to the free end of said lever.

12. In an artificial leg a knee-joint comprising a hinge pivot, a lever fulcrumed thereon having one arm secured to one of the leg members and another arm disposed transversely of the main axis of said memher, a tubular arcuate bearing pivoted forward of its center on the free end of said other arm in a plane perpendicular to said ivot, and an actuating cord loop disposed engthwise of the other leg member and extending throu 11 said bearing.

Signed at Chicago this 16 day of April,

JAMES F. ROWLEY. 

